<?php

class ParameterParser
{
	private $aParams;

	function __construct($aParams=NULL)
	{
		$this->aParams = ($aParams === NULL) ? $_GET : $aParams;
	}

	function getBool($sName, $bDefault=false)
	{
		if (!isset($this->aParams[$sName]) || strlen($this->aParams[$sName]) == 0)
		{
			return $bDefault;
		}

		return (bool) $this->aParams[$sName];
	}

	function getInt($sName, $bDefault=false)
	{
		if (!isset($this->aParams[$sName]) || strlen($this->aParams[$sName]) == 0)
		{
			return $bDefault;
		}

		if (!preg_match('/^[+-]?[0-9]+$/', $this->aParams[$sName]))
		{
			userError("Integer number expected for parameter '$sName'");
		}

		return (int) $this->aParams[$sName];
	}

	function getFloat($sName, $bDefault=false)
	{
		if (!isset($this->aParams[$sName]) || strlen($this->aParams[$sName]) == 0)
		{
			return $bDefault;
		}

		if (!preg_match('/^[+-]?[0-9]*\.?[0-9]+$/', $this->aParams[$sName]))
		{
			userError("Floating-point number expected for parameter '$sName'");
		}

		return (float) $this->aParams[$sName];
	}

	function getString($sName, $bDefault=false)
	{
		if (!isset($this->aParams[$sName]) || strlen($this->aParams[$sName]) == 0)
		{
			return $bDefault;
		}

		return $this->aParams[$sName];
	}

	function getSet($sName, $aValues, $sDefault=false)
	{
		if (!isset($this->aParams[$sName]) || strlen($this->aParams[$sName]) == 0)
		{
			return $sDefault;
		}

		if (!in_array($this->aParams[$sName], $aValues))
		{
			userError("Parameter '$sName' must be one of: ".join(', ', $aValues));
		}

		return $this->aParams[$sName];
	}

	function getStringList($sName, $aDefault=false)
	{
		$sValue = $this->getString($sName);

		if ($sValue)
		{
			return explode(',', $sValue);
		}

		return $aDefault;
	}

	function getPreferredLanguages($sFallback=NULL)
	{
		if ($sFallback === NULL && isset($_SERVER["HTTP_ACCEPT_LANGUAGE"]))
		{
			$sFallback = $_SERVER["HTTP_ACCEPT_LANGUAGE"];
		}

		$aLanguages = array();
		$sLangString = $this->getString('accept-language', $sFallback);

		if ($sLangString)
		{
			if (preg_match_all('/(([a-z]{1,8})(-[a-z]{1,8})?)\s*(;\s*q\s*=\s*(1|0\.[0-9]+))?/i', $sLangString, $aLanguagesParse, PREG_SET_ORDER))
			{
				foreach($aLanguagesParse as $iLang => $aLanguage)
				{
					$aLanguages[$aLanguage[1]] = isset($aLanguage[5])?(float)$aLanguage[5]:1 - ($iLang/100);
					if (!isset($aLanguages[$aLanguage[2]])) $aLanguages[$aLanguage[2]] = $aLanguages[$aLanguage[1]]/10;
				}
				arsort($aLanguages);
			}
		}
		if (!sizeof($aLanguages) && CONST_Default_Language)
		{
			$aLanguages[CONST_Default_Language] = 1;
		}

		foreach($aLanguages as $sLanguage => $fLanguagePref)
		{
			$aLangPrefOrder['short_name:'.$sLanguage] = 'short_name:'.$sLanguage;
			$aLangPrefOrder['name:'.$sLanguage] = 'name:'.$sLanguage;
		}
		$aLangPrefOrder['short_name'] = 'short_name';
		$aLangPrefOrder['name'] = 'name';
		$aLangPrefOrder['brand'] = 'brand';
		foreach($aLanguages as $sLanguage => $fLanguagePref)
		{
			$aLangPrefOrder['official_name:'.$sLanguage] = 'official_name:'.$sLanguage;
		}
		$aLangPrefOrder['official_name'] = 'official_name';
		$aLangPrefOrder['ref'] = 'ref';
		$aLangPrefOrder['type'] = 'type';
		return $aLangPrefOrder;
	}
}